With the unceasing development of display technology, Thin Film Transistor Liquid Crystal Displays (TFT-LCDs) play a leading role in the field of flat panel display as they have the merits of small volume, low power consumption, irradiation-free, etc.
A thin film transistor usually includes a gate electrode, an active layer, a source electrode and a drain electrode, and the gate electrode and the active layer are separated with a gate insulating layer. When a drive signal is input into the gate electrode, the drain electrode can be conducted to the source electrode through the active layer. At present, in more and more thin film transistors, an oxide semiconductor material is used as the active layer. In this case, the active layer may usually be covered by an Etch Stop Layer (ESL) further, so as to protect the active layer, and via holes are formed on the etch stop layer, so that the source electrode and the drain electrode are connected to the active layer through the via holes.
It is found by the inventor in the course of implementing the invention that, the prior art at least suffers from the following issue. In such a scheme that an oxide semiconductor material is used as the active layer, especially when an etch stop layer is employed, overlapping areas between the gate electrode and the source electrode and between the gate electrode and the drain electrode are relatively large, so that a capacitance Cgs formed between the gate electrode and the source electrode and a capacitance Cgd formed between the gate electrode and the drain electrode are relatively large. Thus, the conductive properties of the thin film transistor are affected.